Clamping device

ABSTRACT

A device is provided for clamping the side edges of a receiver to hold it in place while a flexible electrode or a flexible photoconductor is stripped therefrom after charging so that the electrostatic attraction between the member being stripped away and the receiver sheet will not disturb the position of the receiver sheet. The clamps pivot against the receiver tending to stretch it laterally on the platen to hold it tight thereagainst.

United States Patent William A. MacDonald, Jr. Rochester, N.Y.

Mar. 21, 1969 June 15, 1971 Eastman Kodak Company Rochester, N.Y.

Inventor Appl. No. Filed Patented Assignee CLAMPING DEVICE 7 Claims, 2Drawing Figs.

[1.8. CI 269/154, 269/239 Int. Cl B25b 5/04 Field of Search 269/154,

[56] References Cited UNITED STATES PATENTS 1,158,686 11/1915 Henning83/453 X 1,798,240 3/1931 Welter 271/59 UX 2,167,823 8/1939 Backhouse271/59 2,685,927 8/1954 Fechter 269/154 X Primary Examiner-Andrew R.Juhasz Assistant Examiner-Donald D. Evenson Attorneys-Robert W. Hamptonand Gary D. Fields ABSTRACT: A device is provided for clamping the sideedges of a receiver to hold it in place while a flexible electrode or aflexible photoconductor is stripped therefrom after charging so that theelectrostatic attraction between the member being stripped away and thereceiver sheet will not disturb the position of the receiver sheet. Theclamps pivot against the receiver tending to stretch it laterally on theplaten to hold it tight thereagainst.

PATENTEDJUNISIBYI 3584861 ATTORNEYS WILLIAM A. MAC DONALD JR.

CLAMPING DEVICE CROSS-REFERENCE TO RELATED APPLICATION This inventionmay find utility in the device disclosed in my commonly assigned U.S.application Ser. No. 665,915, filed Sept. 6, 1967.

BACKGROUND OF THE INVENTION 1. Field of the Invention The inventionrelates to a clamping device, andmore particularly a clamping device forsecuring one of twomembers which are electrostatically held togetherwhile the other member is stripped therefrom.

2. Description of the Prior Art In electrophotography and related arts,it is common to bring a flexible member into intimate contact withanother member for example, a photoconductive member and a receiversheet or a flexible electrode and a,photoconductive receiver sheet, andapply an electrostatic field during charging which creates anelectrostatic attraction between the members. Insuch arrangements, it isnecessary to subsequently separate the members. If both members aremoving it is relatively simple to separate them. However, in certainprocesses it is desirable to strip one from the other while they remainstationary. The difficulty is compounded where one ofthe members is acut receiver sheet which is to be fed along a predetermined path afterseparation and hence must not be allowed to deviate from that pathduring separation.

SUMMARY OF THE INVENTION The present invention is adapted for use in anelectrophotographic device, such as that disclosed in my commonlyassigned copending U.S. application Ser. No. 665,915, filed Sept. 6,1967 and now abandoned. In that device, a receiver in the form of a webhaving a nonconductive surface and a conductive backing is fed from aroll onto a conductive platen and cut to appropriate lengths to formreceiver sheets. A flexible photoconductor having a conductive backingis lowered onto a receiver sheet on the platen and a potential appliedbetween the platen and the conductive backing of the photoconductor. Ifthe photoconductor is exposed to a pattern of radiation at the sametime, an electrostatic image will be left on the receiver. Afterexposure, the flexible photoconductor is raised, thereby stripping itfrom the receiver sheet.

According to the present invention, to prevent electrostatic attractionfrom pulling the receiver sheet off the platen, clamp means are providedwhich are actuated as the photoconductor is raised to grip the sideedges of the receiver sheet and hold it taut and flat as thephotoconductor is pulled away. Subsequently, the clamps are released andthe cut receiver sheet is fed through a suitable developing stationwhere the electrostatic image thereon is toned and through the fusingstation to fix the image thereon.

Alternatively, the receiver may be coated with a photoconductivematerial. In this case the member which is lowered and raised is merelya flexible electrode. In either case, there is an electrostaticattraction between the receiver and the other member tending to pull thereceiver away from the platen when the members are separated.

More specifically, the clamping means may include paper guides whichreceive the edges of the sheet and have spaced slots therein throughwhich clam'ps may be moved downwardly upon actuation of a clamping barto clamp the receiver to the platen. The clamping bar is moved uponenergization ofa solenoid. After the flexible member is separated fromthe receiver, the solenoid is deenergized permitting the clamps to bespring urged back to their initial position so that the receiver sheetmay be fed through the paper guides to a toning station. The clampspivot so that they tend to stretch the receiver tight across the platen.

Additional novel features and advantages of this invention will becomeapparent from the description which follows, taken in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of theclamping device of this invention, with parts broken away for clarity ofillustration; and

FIG. 2 is a transverse section, on an enlarged scale, taken along line2-2 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT In accordance with thisinvention a platen I0 for supporting a receiver extends between spacedsidewalls 11 and 12 of a frame F which are interconnected by a bottomwall 13. The platen is conductive and may be suitably insulated fromsidewalls 1] and 12 by means not shown. A length of material, such as areceiver sheet 14, which conveniently may include a conductive backingand an insulating layer, may be fed from a roll (not shown) underlongitudinal extending paper guides l5 and 15' which include flangeportions 16 and 16, respectively, extending over the lateral edges ofthe receiver, as shown. As the receiver is advanced it passes underpressure roller 20 and 20' which cooperate with a pair of drive rollerstherebelow, but not shown, which assist in feeding the paper onto platen10 and assist in feeding it off of the platen after charging andexposure.

When the receiver is in position, it may be cut to length as disclosedin my above-mentioned application, and a flexible photoconductive member(not shown) can be lowered onto the receiver. For example, it may belowered by a drive motor 40 which rotates a shaft 41 by means of pulley42 to raise and lower photoconductor support arms 43 by means ofexcentrics 44. One end of the photoconductor is attached to supports 43of FIG. 1, but best seen in my above-mentioned copending application.The other end of the photoconductor is connected to photoconductorsupport arm 45 which is pivotally connected to one end of a link 46whose opposite end is pivoted to sidewall 11. Intermediate the ends oflink 46 is a cam follower, such as roller 47 which rides on cam 48. Cam48 is rotatably driven by motor 40 through pulley 49 to raise and lowersupport arm 45. A more detailed description of the mechanism for raisingand lowering the photoconductor is contained in my above-mentionedapplication. While in the lowered position, a potential may be appliedbetween platen l0 and a conductive backing on the photoconductor toplace an electrostatic charge on the insulating surface of receiver 14.Subsequently to charging or simultaneously therewith the photoconductormay be exposed through its back surface so as to dissipate the chargeand exposed areas on receiver 14 leaving an electrostatic image. Afterexposure the potential is discontinued and the photoconductor is raisedfrom receiver 14 upon energization of motor 40.

Prior to raising the photoconductor, however, clamping devices D and Dare actuated to clamp the receiver so that it will not be pulled out ofpaper guides 15 and 15'. Each clamping device includes a longitudinalchannel having a bottom wall 17 and 17 respectively, interconnectingshort upstanding walls 18 and 18 with longer upstanding walls 19 and19', respectively. Bottom walls 17 and 17 are attached, respectively, toguide 15 and 15. Clamping arms 21 and 21 extend through slots 22 and 22respectively in short legs 18 and 18 and through slots 23 and 23respectively in long legs 19 and 19. As best seen in FIG. 2, slot 22 isrelatively narrow and serves as a pivot-for clamping arm 21 whereas slot23 is relatively long to permit pivotal movement of clamping arm 21.Slots 22 and 23' are similarly constructed. Each clamping arm isprovided with a pressure pad such as pressure pad 24 adapted to moveddownwardly through a slot such as slot 25 in flange 16 of paper guide 15and into engagement with receiver I4, as described below. The oppositeend of each clamping arm 21 is connected to a spring 26 which extendsbetween the clamping arm and paper guide 15', as shown.

A pressure link, such as pressure link 27 extends along the outer sideof leg 19, one end thereof being pivoted to a support or arm 28 which inturn is pivoted to leg 19. The other end link 28 is pivoted intermediatethe ends of an arm 29 whose upper end is pivoted to leg 19. Spaced alonglink 27 above each clamping arm 21 is a pressure pad 31 adapted toengage and pivot pressure arms 21 about slots 22 against the force ofspring 26, as described below.

A similar am 29' as shown in dotted lines in FIG. 1 is provided which isconnected to similar linkage structure, not

shown. Arms 29 and 29' are pivotally connected at their lower ends toyokes 32 and 32', respectively, which in turn are fixedly attached to apivotal rod 33 extending between and journaled in sidewalls 11 and 12.An outwardly extending end of rod 33 is connected to a lever 34 which inturn is connected to arm 35 of solenoid 36. When solenoid 36 isenergized rod 33 is pivoted in a clockwise direction, as viewed in FIG.1 which through yoke 32 which causes arms 29 to be pivoted in acounterclockwise direction so that pressure links 27 are moveddownwardly causing pressure pads 31 to engage clamping arms 21. Thiscauses clamping arms to pivot about slot 22 against the force of springs26 so that clamping pads 24 moved downwardly through slots 25 intoengagement with the side edges of receiver 14. Advantageously, as theclamping pads 24 moved downwardly they will also move outwardly slightlydue to their pivotal movement about slot 22. This tends to stretch thereceiver 14 in a lateral direction so that it is held taut and cannot beraised by the electrostatic attraction between the receiver and thephotoconductor. When solenoid 36 is deenergized, spring 37, encirclingarm 35, will cause rod 33 to be rotated in a counterclockwise directionthereby raising the pressure links. The clamping arms, such as clampingarms 21 will be pivoted back to their initial positions under theinfluence of springs 26.

When motor 40 is energized to raise the photoconductor, cam 48 will berotated in a clockwise direction through the position shown in FIG. 1 sothat the leading end of cam 48 closes switch 50 in the circuit tosolenoid 36. As cam 48 continues to rotate, cam follower 47 will beraised to raise the photoconductor. While the photoconductor is in thefully raised position, the trailing end of cam 48 will pass the switchjust before motor 40 is deenergized. This will cause switch 50 to beopened and solenoid 36 to be deenergized.

It will be understood that for some applications it may be desirable touse a receiver having a photoconductive surface thereon. In that casethe member whichis raised and lowered may be a flexible conductiveelectrode.

From the foregoing, the advantages of this invention are readilyapparent. A means has been provided wherein a receiver sheet may befirmly clamped to a platen while a flexible member is separatedtherefrom after charging so that the electrostatic attraction betweenthe two will not cause the receiver to be pulled out of its guides.Conveniently, a series of pressure pads space along the longitudinaledges of the receiver are adapted to pivot through an arc so as to gripthe edges of the receiver and pull it taut.

The invention has been described in detail with particular references topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

I claim:

1. An apparatus for clamping lateral edges of a length of material, saidapparatus comprising:

a platen, having side edges, for supporting said length of material fedfrom a first end of said platen toward a second end thereof;

respective clamping means adjacent each side edge of said platen, eachclamping means being movable from a first position spaced from said sideedges to a second position in engagement with said platen to clamp thelateral edges of said length ofmaterial to said platen;

actuatable means coupled to each of said clamping means for moving saidclamping means from said first position to said second position; and

respective guide means along each side edge of said platen for guidingsaid length of material, each said guide means having means defining atleast one opening through which each of said clamping means is movablefrom said first position to said second position.

2. An apparatus for clamping lateral edges of a cut sheet comprising:

a platen, having side edges, for supporting said cut sheet fed from afirst end of said platen toward a second end thereof;

a guide along each side edge of said platen for guiding said sheet, eachguide having means defining a plurality of slots;

a plurality of clamping arms mounted adjacent each side edge of saidplaten for pivotal movement from a first position spaced from said sideedges to a second position in engagement with said platen a foot on eachof said clamping arms, each movable through one of said slots uponmovement of said arms from said first position to said second positionto clamp the lateral edges of said sheet against said platen; and

actuatable moving mean coupled to said clamping arms for moving saidclamping arms from said first position to said second position 3. In anelectrophotographic device, a receiver sheet clamping apparatuscomprising:

a platen, having side edges, for supporting a receiver sheet havinglateral edges, fed from a first end of said platen toward a second endthereof;

a guide along each side edge of said platen for guiding said receiversheet, each guide having means defining a plurality of slots;

a support means along each side edge of said platen;

a plurality of clamping arms having feet thereon, said clamping armsbeing pivotally mounted on each of said support means for movement froma first position wherein said feet are spaced from said platen to asecond position wherein said feet move through said slots intoengagement with said platen to grip said lateral edges of said receiversheet therebetween;

a pressure link extending along each of said support means engageablewith said arms;

a pair of spaced pivot arms respectively pivotally interconnecting eachof said pressure links with said respective support means;

linkage means connected to at least one of said pivot arms;

and

actuatable moving means connected to said linkage means for moving saidpressure links into engagement with said clamping arms to moved saidclamping arms from said first position to said second position.

4. In an electrophotographic device, as claimed in claim 3,

said support means comprising:

generally U-shaped members having a long leg and a short leginterconnected by a base, said base being attached to said platen withsaid short leg closest to said side edges of said platen;

means defining opposed slots in said long and short legs through whichsaid arms extend, said slots in said short legs serving as pivots forsaid arms and said slots in said long legs being of sufficient size tofacilitate pivotal movement of said arms from said first position tosaid second position.

5. In an electrophotographic device, as claimed in claim 4,

further comprising:

spring means connected to each of said arms urging said arms toward saidfirst position.

6. In an electrophotographic device, as claimed in claim 3,

wherein said linkage means includes:

a rotatable rod extending transversely ofsaid platen;

a pair of spaced yokes each having a first end fixedly connected to saidrod and each having a second end pivotally connected to one of each ofsaid pair of pivot arms; and

a lever having a first and second end, said first end being fixedlyconnected to said rod; and

wherein said moving means includes:

a solenoid connected to said second end of said lever for rotating saidrod upon actuation of said solenoid to move said pressure links intoengagement with said clamping arms.

7. An apparatus for clamping lateral edges of a cut sheet comprising:

a platen, having side edges, for supporting said cut sheet fed from afirst end of said platen toward a second end thereof;

a plurality of clamping arms mounted adjacent each side edge of saidplaten for pivotal movement from a first posi-

1. An apparatus for clamping lateral edges of a length of material, saidapparatus comprising: a platen, having side edges, for supporting saidlength of material fed from a first end of said platen toward a secondend thereof; respective clamping means adjacent each side edge of saidplaten, each clamping means being movable from a first position spacedfrom said side edges to a second position in engagement with said platento clamp the lateral edges of said length of material to said platen;actuatable means coupled to each of said clamping means for moving saidclamping means from said first position to said second position; andrespective guide means along each side edge of said platen for guidingsaid length of material, each said guide means having means defining atleast one opening through which each of said clamping means is movablefrom said first position to said second position.
 2. An apparatus forclamping lateral edges of a cut sheet comprising: a platen, having sideedges, for supporting said cut sheet fed from a first end of said platentoward a second end thereof; a guide along each side edge of said platenfor guiding said sheet, each guide having means defining a plurality ofslots; a plurality of clamping arms mounted adjacent each side edge ofsaid platen for pivotal movement from a first position spaced from saidside edges to a second position in engagement with said platen a foot oneach of said clamping arms, each movable through one of said slots uponmovement of said arms from said first position to said second positionto clamp the lateral edges of said sheet against said platen; andactuatable moving mean coupled to said clamping arms for moving saidclamping arms from said first position to said second position
 3. In anelectrophotographic device, a receiver sheet clamping apparatuscomprising: a platen, having side edges, for supporting a receiver sheethaving lateral edges, fed from a first end of said platen toward asecond end thereof; a guide along each side edge of said platen forguiding said receiver sheet, each guide having means defining aplurality of slots; a support means along each side edge of said platen;a plurality of clamping arms having feet thereon, said clamping armsbeing pivotally mounted on each of said support means for movement froma first position wherein said feet are spaced from said platen to asecond position wherein said feet move through said slots intoengagement with said platen to grip said lateral edges of said receiversheet therebetween; a pressure link extending along each of said supportmeans engageable with said arms; a pair of spaced pivot armsrespectively pivotally interconnecting each of said pressure links withsaid respective support means; linkage means connected to at least oneof said pivot arms; and actuatable moving means connected to saidlinkage means for moving said pressure links into engagement with saidclamping arms to moved said clamping arms from said first position tosaid second position.
 4. In an electrophotographic device, as claimed inclaim 3, said support means comprising: generally U-shaped membershaving a long leg and a short leg interconnected by a base, said basebeing attached to said platen with said short leg closest to said sideedges of said platen; means defining opposed slots in said long andshort legs through which said arms extend, said slots in said short legsserving as pivots for said arms and said Slots in said long legs beingof sufficient size to facilitate pivotal movement of said arms from saidfirst position to said second position.
 5. In an electrophotographicdevice, as claimed in claim 4, further comprising: spring meansconnected to each of said arms urging said arms toward said firstposition.
 6. In an electrophotographic device, as claimed in claim 3,wherein said linkage means includes: a rotatable rod extendingtransversely of said platen; a pair of spaced yokes each having a firstend fixedly connected to said rod and each having a second end pivotallyconnected to one of each of said pair of pivot arms; and a lever havinga first and second end, said first end being fixedly connected to saidrod; and wherein said moving means includes: a solenoid connected tosaid second end of said lever for rotating said rod upon actuation ofsaid solenoid to move said pressure links into engagement with saidclamping arms.
 7. An apparatus for clamping lateral edges of a cut sheetcomprising: a platen, having side edges, for supporting said cut sheetfed from a first end of said platen toward a second end thereof; aplurality of clamping arms mounted adjacent each side edge of saidplaten for pivotal movement from a first position spaced from said sideedges to a second position in engagement with said platen; a generallyU-shaped support extending along each side of said platen, each supporthaving spaced legs with means defining a plurality of opposed slotstherein through which said clamping arms extend, said slots in one ofsaid legs serving as a fulcrum about which said arms pivot upon movementfrom one of said positions to the other of said positions; andactuatable moving means coupled to said clamping arms for moving saidclamping arms from said first position to said second position.